Locomotive-boiler furnace.



WILLETT.

B 1L Fi FURNACE.

H MW. 8, 191 6.

OMOTWE APPLICATION A. H. WILLETT LCFCOMOTIVE BOILER FURNACE.

APPLICATION FILED JAN. s. 1916.

Pammedhne 12, 191?.

2 SHEETS-SHEET 2- to locomotive boiler fireboxes of all in a an rm.

ALFRED H. WILLETT, OF WEST NEW YORK, NEW JERSEY, ASSIGNOR TO AMERICAN ARCH COMPANY, OF NEW YORK,

N. Y., A CORPORATION OF DELAWARE.

LOCOMOTIVE-BOILER FURNACE.

Specification of Letters Patent.

Patented June 12, 1917.

Application filed January 8, 1916. Serial No. 71,063.

To all whom it may concern:

Be it known that I, ALFRED H. lViLLETT, a citizen of the United States, and a resident of lVest New York, Hudson county, New Jersey, have invented certain new and useful Improvements in Locomotive-Boiler Furnaces, of which the following is a specification.

My invention relates to improvements in locomotive boiler furnaces and has particular reference to improvements inso-called Gaines combustion chamber fireboxes for locomotives. In its best form the Gaines type of firebox contains a cross wall through which air is admitted and combined with a rearwardly overhanging inclined arch or baflle supported by water-circulating arch tubes. The archtubes before referred to extend from the throat-sheet, 6., the lower portion of the flue sheet, across the top'of the cross wall and thence through the rear sheet of the firebox.

In my experience with the Gaines combustion chamber type of firebox, I have frequently encountered locomotive fireboxes in which the throat sheet is too shallow to allow the desired application of the combined combustion chamber and refractory arch principle of construction. That is, in many cases it is not possible to employ arch tubes between the lower part of the flue sheet and the rear sheet and hence the overhanging arch cannot well be employed. The object of this invention is to obviate the difficulty presented by fireboxes having shallow throats and to so modify the construction of the Gaines furnace that it shall be applicable types including those of the shallow-throat sheet type.

My invention will be more readily understood by reference to the drawings that form part of this specification and in which: Figure l is a vertical longitudinal section of a locomotive boiler firebox embodying my invention ;Fig. 2 is a plan View thereof on the line XX of Fig. 1 projected from Fig. 1;Fig. 3, is a vertical transverse half section on the line Y-Y of Fig. 1;and Fig. 4 is a similar half-section on the irregular line ZZ of Fig. 1, the cross wall, and the arch bricks being omitted to better disclose the forms and positions of the Water-circulating arch tubes. The difficulty here mentioned is encountered most frequently in the fireboxes of locomotive boilers having barrels of maximum dimensions, and in which the bottom of the barrel is only slightly above the plane of the grate of the firebox. The difliculty is also met in boilers of the type characterized by level grates, i. 6., those in which the grate is substantially in a horizontal plane, the height of which above the wheels is determined by the lowest point to which the throat and the rear sheets of the boiler can be carried. In all such cases the lowermost flues in the flue sheet are close to the grate line and forward end of the mud ing the grate from rear sheet to throat sheet,

and the installation of an arch is not at tempted. It is now well settled that, although the installation ofthe Gaines construction in a locomotive firebox diminishes the grate area by occupying a portion of the space in the front end of the firebox, the net results secured upon the remaining grate area, and the saving of fuel, more than compensate for the subtracted grate area. It is therefore especially desirable that the combined cross wall and arch of the improved Gaines construction shall be applied to locomotives of the class herein described, the peculiarities of which have hitherto prevented the installation of refractory arches and the attainment of the well-known benefits thereof.

I have devised a very simple solution of the problem above presented, consisting chiefly in abandoning the throat sheet as the point of attachment for arch tubes and in attaching the arch tubes to the side sheets of the firebox adjacent the juncture thereof with the flue sheets. As a necessary incident I position the tubes and the Gaines cross wall in such manner that the cross wall serves to support the tubes, and yet thereof.

' The other familiar parts may be identified as follows :the fiues, 4;the barrel, 5; the mud-ring, 6;the grate, 7;the rear sheet, 8;the cross sheet, 9;and, the side sheets, 10. The parts characteristic of a Gaines firebox are the bridge, 11;-the crosswall, 12, containing the air ducts, 13;the inclined arch, 14;the combustion chamber, 15 ;the bottom, 16, thereof.;-'and, the cinder-hopper, 17, which closes an opening in the bottom, 16, of the combustion chamber, 15.

To the parts thus identified, I add a plurality of water -circulating arch tubes, at. Therear portions of these arch tubes are of usual straight form and their ends are secured in the upper part of the rear sheet, 8, of the fire box. The tubes, a, are usually spaced at equal distances, and preferably are parallel. They serve to support the component refractory bricks of the arch, 14. In constructing the top, 12, of the cross wall, 12, I employ bricks which form saddles that receive and hold the arch tubes, a. The bricks, 12, also furnish end-abutments for the arch, 14. In some cases I find it desirable to relieve the bricks, 12, from all or a greater part of the weight of the tubes, a, and arch, 14, and in such cases I employ the so-called back-stay or buck-stay part, 12", of the cross wall, 12, as the chief intermediate support of the tubes, a.

It will be clear that the throat sheet, 3, and the throat leg, 3, boilers, do not provide proper space for the reception of the lower ends of the arch tubes and I do not attempt to securethem-therein. Instead, as best shown in Figs. 2 and 4, I bend the lower portions, 0., of the arch tubes outwardly, that is, downwardly and laterally, and secure their ends in openings provided in the lower forward corners of respective side sheets, 10. Preferably, the tubes are also bent downwardly just forward'of the cross wall, as shown at B, Fig. 1.

of the illustrated The several bends-conform to gentle curves and do not materially obstruct the flow of water through the arch tubes. The tubes upon the opposite sides of the center line of the firebox are bent laterally in opposite directions as shown in Fig. 2.

In the manner described, the tubes are made to enter the side water legs, 10, of the boiler at the proper height above the mud ring, 6, and are most conveniently located for purposes of installation, inspection and repair.

Particular attention is called to the advantageous freedom of expansion and contraction, provided by the several bends in the tubes. It should be noted that the intermediate portions, 0, of the arch tubes, a, are straight, and this is true also of the saddle portions of the wall, 12, and buckstay, 12". It follows that the cross wall in no wise interferes with the free longitudinal expansion and contraction of the arch tubes.

By means of my invention, refractory front arches and cross walls may be installed in vthe fireboxes of practically all locomotives. The advantagesof the invention are not limited strictly to the fireboxes of the shallow-throat-sheet type.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:- I

The improvement herein described, comprising a locomotive firebox, its mud ring, throat sheet, and side sheets, in combination with a cross wall in said firebox rearward of said throat sheet, a combustion chamber being formed between said wall and throat sheet, a floor forming the bottom of said combustion chamber, a plurality of watercireulating arch tubes having their forward ends secured in the side sheets at points forward of said wall and rearward of said throat sheet, said tubes extending thence upwardly and rearwardly beyond said wall, and an arch extending rearwardly from said wall and composed of refractory bricks resting upon said tubes.

In testimony whereof, I have hereunto set my hand this 28th day of December, 1915.

' ALFRED H. WILLETT. 

